This invention relates generally to gas turbine engines, more particularly to combustors used with gas turbine engines.
Known turbine engines include a compressor for compressing air which is suitably mixed with a fuel and channeled to a combustor wherein the mixture is ignited within a combustion chamber for generating hot combustion gases. More specifically, at least some known combustors include a dome assembly, a cowling, and liners to channel the combustion gases to a turbine, which extracts energy from the combustion gases for powering the compressor, as well as producing useful work to propel an aircraft in flight or to power a load, such as an electrical generator. Moreover, at least some known combustors include ignition devices, such as ignitors, primer nozzles, and/or pilot fuel nozzles, which are used during pre-selected engine operations to facilitate igniting the mixture within the combustion gases.
At least some known fuel injectors are dual fuel injectors capable of supplying a liquid fuel, a gaseous fuel, or a mixture of liquid and gaseous fuels to the combustor. To facilitate reducing emissions within such combustors, at least some known combustors include water injection systems to facilitate nitrous oxide emission abatement. Within such systems, the water is premixed with the fuel during liquid fuel operation and is injected into the combustor through the fuel injector. Combining the water with liquid fuel in a single fuel circuit provides a design compromise, as the fuel/water mixture is optimized for flow and atomization, rather than requiring the liquid fuel and water to be individually optimized. However, within known fuel injectors, the water injection may provide only limited benefits, as the combined fuel/water mixture may become unmanageable at higher fuel flows.